Unico Drive serial interface error

[RicK.]

1) I am trying to talk to a Unico drive via a serial port. I receive a -1073807339 error in the Vesa Read in the Drive Send VI. However, the VISA write doesn't seem to be getting to the drive properly as it should effect the speed even though the read doesn't work. I have been able to talk to the drive in HTBasic. I checked that the port settings are correct. I checked the CRC creation. The command is to be sent without any character trailing the CRC character. I turned that off in the VISA open. Any suggestions what else to try?
2) I also found that the VISA duplicate output doesn't work in the VISA open. That block element outputs an empty VESA device addr when "probed". Any idea why that isn't working?

[Sarah Thompson]

RicK,
The error -1073807339 is almost always caused by a timeout. Adding a wait function, running in Highlight execution mode, or running with Ni-Spy will slow the processor and give the instrument time to read and generate a response. For more information, check out our VISA support page at: http://www.ni.com/support/visasupp.htm


Sarah Fenney
Applications Engineer
National Instruments